A currently marketed automatic cigarette packing machine comprises a user interface device, which communicates on one side with a control unit of the packing machine and, on the other, with an operator. Communication with the operator may be either local, i.e. the operator is physically close to the machine, or remote (over a local TCP/IP protocol network and/or Internet network). Currently marketed user interface devices employ an SQL database comprising a history data table, in which the values assumed by various control variables during particular events are memorized. More specifically, the history data table memorizes all the machine stop messages, i.e. relating to events resulting in stoppage of the machine, and, for each machine stop message, normally memorizes the type of event the message refers to, any parameters connected with the event, machine stoppage start date and time, machine stoppage end date and time, a shift identification code, and a machine identification code. The history data table is queue-managed, in the sense that a new event, as opposed to being written over an existing event in the table, is added “to the end of the queue”; and, to maintain a reasonable size of the history data table, events stored over and above a given threshold period (e.g. 1 month) are periodically deleted.
The information stored in the history data table is not always sufficient to determine what has actually caused stoppage of the packing machine. That is, even in the event of actual problems on the packing machine, the machine is frequently stopped by the operator, for control, adjustment, and maintenance purposes, prior to automatic stoppage by the control unit. As a result, most of the machine stoppages in the history data table are recorded as operator-induced, with no way of determining what has induced the operator to stop the machine.
Moreover, even when the machine is stopped by the control unit on the basis of a malfunction signal, only the cause of the stoppage is known, with no information as to what lies beneath the cause.